Electric fuel pumps located in vehicle fuel tanks have supplanted the older fuel systems in which vacuum was used to pull fuel from the fuel source to the carburetor. This is especially true in fuel systems utilizing fuel injection. These fuel pumps are operated at high speeds and in most cases utilize positive displacement type pumps which inherently have a pulsating system. These pumps may have pressure range from 12 pounds per square inch (psi) to 75 psi. Especially in passenger vehicles, it is desirable to have the fuel pumps operate in such a manner that passengers are not conscious of any pulsating noise or vibration. Since most fuel tanks are mounted in the rear of the vehicle, it is important that passengers in the rear seats are not disturbed by the pump operation.
Accordingly, there have been many efforts to reduce pump noise and vibration. Various mounting devices and shielding walls have been suggested as illustrated in the disclosures of the following U.S. patents:
Horn et al, U.S. Pat. No. 3,014,623 (1961) PA1 Ringwald et al, U.S. Pat. No. 4,231,719 (1980) PA1 Otto et al U.S. Pat. No. 4,306,844 (1981) PA1 Beardmore U.S. Pat. No. 4,590,964 (1986) PA1 Tuckey U.S. Pat. No 4,569,637 (1986) PA1 Takahashi et al U.S. Pat. No. 4,591,319 (1986)
It is an object of the present invention to provide an electric fuel pump combination which achieves a significant lowering of vibration and pulse noise while providing an inexpensive mounting system.
It is a further object to provide a pump mounting combination which is versatile in adaptation to varying tank sizes and useful in a wide range of pump ratings as to operating pressures.
It is a further object to provide a pump mounting unit which maintains pump pressure in the fuel lines during a shut-off period and thus reduces delay time in a restart cycle due to priming time.
Further objects and features of the invention will be apparent in the following description and claims in which the principles of the invention are set forth together with details to enable persons skilled in the art to practice the invention, all in connection with the best modes presently contemplated for the invention.